Etching-machine.



H. SCHEDLER. BTGHING MAGHINE. APPLIOATION HL'BD SEPT. 2s, 1908.

940,480.I Patented Nov. 16,1909.

W/ TNE SSE S N VE N 7"0/? A TTOHNEYS HERMANN SGHEDLER, OF NEW YORK, N.Y.

ETCHING- MACHINE.

Specification of Letters Patent.

Patented Nov. 16, 1909.

Application filed September 28, 1908. Serial No. 455,056.

To all whom it may concern.'

Be it known that LHERMANN SG1-momma citizen of the United States, and aresidentof the city of New York, borough of Manhattan, in the county andState of New York, have invented .a new and lmproved Etching-Machine, ofwhich the following is a full, clear, and exactdescription.

My invention relates to etching machines of the type in which a plate orother article to be etched is exposed to the action of free acid in atrough.

The particular purposes of my improvement are as follows: 1. Tofacilitate the free circulation of the acid relatively to the article tobe etched, and to cause the commingling of air with the acid in order tofacilitate the action of the acid. 2. To cause thorough etching of theplate without the use of brushes making actual contact therewith. 3. Toemploy paddles or agitators made in peculiar form in order to facilitatethe two objects above stated. 4.-. To enable the operator to readilyadjust the depth to which the agitators or paddles dip into the acid.

Reference is to be had to the accompanying drawings forming a part ofthis specilication, in which similar characters of reference indicatecorresponding parts in all the gures.

Figure 1 is a vertical section upon the line 1 1 in Fig. 2, looking inthe direction of the arrow, and showing the trough, a plate resting inthe bottom thereof, free acid covering the plate, and my improvedpaddles dipping into this acid, the view further showing how theimmersion of the paddles is controllable at will, and also how thepaddles are actua-ted; Fig. 2 is a plan view of the complete apparatusshown in Fig. 1; Fig. 3 is an enlarged cross section upon the line 3 8in Fig. 1, looking in the direction of the arrow, and showing how thepaddles are mounted upon the movable frame; Fig. 4l is a detail showing'in perspective one of the paddles, and Fig. 5 is a detail sectional viewon the line 5-5 in Fig. 1, showing how the adjusting wedges are fittedin position and how they are used in order to regulate the depth of thepaddles in the acid.

A trough is shown at 5 and is provided with sloping ends 6 and with sidewalls 7. A plate S to be etched is rested on the bottom of the troughand covered with a quantity of free acid 9. The paddles are shown at 10and may be made of wood, hard rubber or other acid-proof material. Eachpaddle is provided with openings 11, 12 of different sizes, extendingentirely through it, and is further provided with slots 13, 14 extendingin different directions and cut into the edges of the paddles atdiierent points, the slots 13 being cut into the bottoni and the slots14 being cut into the sides of the paddles. A number of longitudinalbars 15 extend lengthwise ofthe trough, and disposed across these barsand connected rigidly with the under side thereof are cross bars 16, thelongitudinal bars 15 and cross bars 16 being rigid in relation to eachother, and together constituting a movable frame.

The paddles 10 are secured firmly upon this frame and are movable withit. Handles 17, 18 are provided for the frame in order to enable it tobe moved relatively to the trough. lvlounted at opposite ends of thetrough 5 are lugs 19, 20, and engaging the latter are wedges 21, Bolts23 extend upwardly from the lugs 19 and 20, and revolubly lit-ted uponthese bolts are nuts 24. Straps 25 are held down by the nuts 24, in suchmanner as to clamp the wedges 21 and 22, and yet allow the longitudinalbars 15 to move endwise within proper' limits.

The operation of my device is as follows: The parts being assembled asabove described, and the plate 8 being in the bottom of the trough andcovered by the acid 9, the operator adjusts the wedges 21, 22 so as togive the paddles 10 a desired degree of immersion in the acid 9. Theoperator next grasps either handle 17 or 18 and slides the framelongitudinally in the general direction of the length of the trough. lndoing this, the acid 9 is forced through the various openings 11, 12 andslots 13, 14, and thereby caused to flow in divers directions. Moreover,this action causes more or less air to become commingled with the acid,and this air is thus brought into minute contact with the plate 8 to beetched. The current of the etching fluid, created by so being forcedthrough the opening, draws with it any sediment deposited at the bottomand along the lines being etched, which otherwise would act as aprotection against such parts being etched deeper.

l have made the discovery that if acid be brought into minute contactwith air, as, for instance, by spraying the air into the acid, a largeamount of air is absorbed by the acid, and this air appears to intensifythe effect of the acid, thereby promoting economy in the use of the acidas well as causing the acid to do better work in the matter of etching.I have also made the discovery that by arranging the paddles l() so thatthe slots 13 of one paddle extend in different directions relatively tothe slots 13 of another paddle, as indicated in dotted lines in Fig. 2,the general effect of the acid is greatly improved. rhis is simplybecause the air is brought into better contact with the acid, and theacid holding the air by absorption is in turn brought into bettercontact with the article to be etched. I have also discovered that bymaking the openings ll, l2 of different sizes the stirring of the acidis rendered much more eectiveowing, I suppose, to the fact that the acidcan pass through a large opening more readily than through a smallerone, and consequently, as the paddles l0 are moved through the liquid,eddies are formed which have an important effect in stirring the acid.

lf the acid becomes weak, because of prolonged use, it is sometimesdesirable to lower the paddles so as to bring them into closer proximitywith the article to be etched. The operator thereupon loosens the nutsZet, adjusts the wedges 21, 22 by drawing them slightly outward from theends of the trough, and tightens the nuts 24k. The frame may now be slidlongitudinally in the general direction of the trough, as before, theonly difference being that the bottoms of the paddles are closer to theplate to be etched. This being done, the agitation of the acidrelatively to the plate is somewhat increased. By thus adjusting theframe carrying the paddles, the work of the acid may be rendered morethoroughly uniform, so that the time taken to etch the plate with oldacid need not vary from that required for etching a plate with new acid.The quality of the etching is also greatly improved.

I am aware that in etching apparatus of the kind heretofore employed,brushes dip ping into an acid have been employed. The purpose of thesebrushes, however, has been to engage directly the surface to be etched,

and their use has necessarily been attended with more or less impairmentin the quality of the work done. What I seek to do is to cause the acidto produce a maximum effect and yet to prevent the actual contact of thepaddles with the surface to be etched.

Having thus described my invention, I claim as new and desire to secureby Letters Patent:

l. An etching machine, comprising a paddle provided with holes extendingthrough it, and further provided with slots, said slots forming angleswith each other, a frame connected with said paddles for the purpose ofactuating the same, and a trough partially inclosing said paddles andadapted to hold an acid.

2. In'an etching machine, the combination of a trough provided withlugs, wedges engaging said lugs and movable -relatively to the same, aframe resting upon said wedges and movable relatively to said trough,and paddles connected with said frame and depending into said trough forthe purpose of agitating an acid therein.

3. In an etching machine, the combination of a trough, a frame movablerelatively to the same, and a paddle mounted upon said frame, saidpaddle being provided with nmtilations of different sizes extendingthrough it.

4t. A device of the character described, comprising a trough, a framemovable relatively to the same, and a paddle carried by said frame andextending into said trough, said paddle being provided with mutilationsextending entirely through it, the said mutilations being of differentsizes, some of said mutilations forming angles relatively to others ofsaid mutilations for the purpose otl facilitating the circulation ofliquid through said paddle.

In testimony whereof I have signed my name to this specication in thepresence of two subscribing witnesses.

HERMANN SCHEDLER.

lVitnesses VAL'roN HARRISON,

JOI-IN l?. DAvIs.

